All the signs of incipient activism and uprising, from Tahrir square to Zuccotti Park to [the recent] shutdown of the Internet to protest web censorship. People are getting smart and getting connected.

We believe that we live in the 'age of information,' that there has been an information 'explosion,' an information 'revolution.' While in a certain narrow sense this is the case, in many important ways just the opposite is true. We also live at a moment of deep ignorance, when vital knowledge that humans have always possessed about who we are and where we live seems beyond our reach. An Unenlightenment. An age of missing information.

That's when the vast consensus of the world's climatologists, brought together by the UN and The Intergovernmental Panel on Climate Change, really announced that this was going on, and since then the accumulation of data and wickedly hot years has served to only congeal that consensus much more firmly.

We have to get our states to adopt what are called "renewable portfolio standards" pledging to use a lot of renewable energy by 2015 or 2020. We have to work with businesses and shops to get them engaged in the same way.

A third of summer sea ice in the Arctic is gone, the oceans are 30 percent more acidic, and since warm air holds more water vapor than cold, the atmosphere over the oceans is a shocking five percent wetter, loading the dice for devastating floods.

If we had about 100 years, that sort of slow cultural conversion would be exactly the thing to do. But physics is calling the tune here. We've got to respond to a timetable that physics has set for us.

There is no ideal Christmas; only the one Christmas you decide to make as a reflection of your values, desires, affections, traditions.